KVM: VMX: Consume pending LAPIC INIT event when exit on INIT_SIGNAL
authorLiran Alon <liran.alon@oracle.com>
Mon, 11 Nov 2019 12:16:05 +0000 (14:16 +0200)
committerPaolo Bonzini <pbonzini@redhat.com>
Fri, 15 Nov 2019 10:44:01 +0000 (11:44 +0100)
commite64a8508234afb17a15d1aa98e8c1434fc207755
treeb872ded857ec66c80b2b9d9e42a411d9a82a8948
parent27cbe7d61898a1d1d39be32e5acff7d4be6e9d87
KVM: VMX: Consume pending LAPIC INIT event when exit on INIT_SIGNAL

Intel SDM section 25.2 OTHER CAUSES OF VM EXITS specifies the following
on INIT signals: "Such exits do not modify register state or clear pending
events as they would outside of VMX operation."

When commit 4b9852f4f389 ("KVM: x86: Fix INIT signal handling in various CPU states")
was applied, I interepted above Intel SDM statement such that
INIT_SIGNAL exit don’t consume the LAPIC INIT pending event.

However, when Nadav Amit run matching kvm-unit-test on a bare-metal
machine, it turned out my interpetation was wrong. i.e. INIT_SIGNAL
exit does consume the LAPIC INIT pending event.
(See: https://www.spinics.net/lists/kvm/msg196757.html)

Therefore, fix KVM code to behave as observed on bare-metal.

Fixes: 4b9852f4f389 ("KVM: x86: Fix INIT signal handling in various CPU states")
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/vmx/nested.c